Erm, every device on earth with any kind of audio out can "have" external fm transmitter - you just plug any 2$ transmitter to audio out (instead of headphones, for example), and voila. But, it's hardly a "feature" of a phone, and it's funny with iPhones (as always...), that they're trying to sell it as something "special".

Heck, it's even trivial to construct own batter-powered, 1W FM transmitter, which will outrun hell of anything sold (due to law limitations put on those). But the whole fun is to have it build-in, without need to carry external part, if unnecessary.

/Estel